114 A CHEMICAL SIGN OF LIFE 
furnished by Eimer & Amend when the biometer is 
ordered.) Each of the chambers has a capacity of 20 
to 25 c.c. and is provided with the platinum electrodes 
n and m for stimulation purposes, and also with a 
glass stopper S or R, which can be sealed with mercury. 
The air pump is connected through J and the barium 
hydroxide solution is introduced through V to d and f, 
where the drops are to be formed. 
How to set up the biometer—In order to get up this 
apparatus, the following materials will be necessary: 
one biometer proper; two ordinary three-way stopcocks; 
one nitrometer; one ordinary glass stopcock; one 
water pump; one mercury burette, made of four or five 
inches of any broken burette; one bottle with a side 
neck at the bottom of about 300 c.c. capacity (aspirator 
bottles); two large carboys; one capillary T-tube to be 
bent to fit the biometer proper at Q and F; three 
pinchcocks; one empty acid bottle for a half-saturated 
solution of barium hydroxide; two CaCl, tubes or wash- 
bottles to protect barium hydroxide, and one carboy; 
one 10o-pound can of Greenbank alkali; soo g. of C.P. 
barium hydroxide; one yard of thick-walled pressure 
tubing; one yard of good antimony tubing to fit the 
ordinary glass tubing; a little sealing wax; 200 c.c. of 
redistilled mercury; a few yards of glass tubing of or- 
dinary sizes. 
Excepting for the biometer proper, most of the 
materials mentioned above can be found in an ordinary 
laboratory or can be substituted with homemade appa- 
ratus without losing the accuracy of the method. 
With these materials on hand, the apparatus can be 
set up without any difficulty if one follows the figure very 
